Contour sewing machines



G. J. ABEL CONTOUR SEWING MACHINES April 7, 1959 6 Sheets-Sheet 1 FiledFeb. 15, 1956 lllll 2% a d S d S M. m 2

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INVENTOR. George J. Abel ATTORNEY WITNESS I G. J. ABEL CONTOUR SEWINGMACHINES April 7 1959 6 Sheets -Sheet 3 Filed Feb. 15, 1956 A .A 7/ m flw V m W 9 8% m \a m w Y m M M m VJ T We OW m w G V. B B

WITNESS G. J. ABEL CONTOUR SEWING MACHINES April 7, 1959 6 Sheets-Sheet4 Filed Feb. 15, 1956 L L O 0 2 S 1 2 3 4 R H l l R R m w m m u m c c cM M LVI L .ll .Ilm mm 0 A 0 m r 3 m A fl .n n A T L E 00 DI m F m m S Il S C C P M H o o m 9 P R 4 G H R M T 1| H a C m z m m m 4 T S M m" dRHHM m c RH" c T S c s n X H m M m N H m H, m WL C .m

INVENTOR. Gearge J; Abel 84W v ATTORNEY WITNESS G. J. ABEL CONTOURSEWING MACHINES April 7, 1959 6' Sheets-Sheet 5 Filed Feb. 15, 1956INVENTOR. George J. Abel WITNESS TTORNEY I April 1959 G.VJ. ABEL2,880,683

CONTOUR sswmc MACHINES I Filed Feb. 15, 1956 6 Sheets-Sheet 6 CYCLEEMERG.

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TORNE Y United States. Patent CONTOUR SEWING MACHINES George J. Abel,Watchung, N.J., assignor to The Singer Manufacturing Company, Elizabeth,N.J., a corporation of New Jersey Application February 15, 1956, SerialNo. 565,569

2 Claims. (Cl. 112-2) This invention relates to contour sewing machinesand more particularly to apparatus and control means for presentingmaterial automatically to the stitching instrumentalities of aconventional sewing machine to effect a seam along a predeterminedcontour path of compound curvature.

Prior art devices in this field have been deficient generally in thatthe material to be sewn has been confined to move inbut two componentlinear directions with respect to the stitching instrumentalities. Thisprior presentation of the material does not always accord with thenormal direction of machine feed and adversely affects the stitchformation and the appearance of the finished seam particularly whereseam paths of compound curvature are involved.

It is a primary object of this invention to provide apparatus andcontrol means therefor for sewing automatically along a predeterminedpath of compound curvature using a conventional sewing machine.-

It is a further object of this invention to provide material controlmeans for a sewing machine including feeding means whereby the materialis automatically guided to and fed past the stitching instrumentalitiesin the normal direction of machine feed in making a seam following apredetermined path of compound curvature.

With the above and other objects in view, as will hereinafter appear,the invention comprises the devices, combinations, and arrangements ofparts hereinafter set forth and illustrated in the accompanying drawingsof a preferred embodiment of the invention, from which the severalfeatures of the invention and the advantages attained thereby will bereadily understood by those skilled in the art.

In the drawings:

Fig. 1 is a plan view of apparatus embodying the invention.

Fig. 2 is an elevational view of the apparatus of Fig. 1.

Fig. 3 is a partial view taken on line 33 of Fig. 2.

Fig. 4 is a detail plan view of the cam drive mechanism of Fig. 3.

Fig. 5 is a longitudinal sectional view taken substantially on line 55of Fig. 4.

Fig. 6 is a diagram of the electric control system for the machine ofFig. 1.

Fig. 7 is a detail bottom plan view of a modified cam drive mechanism.

Fig. 8 is a longitudinal sectional view taken substantially on line 88of Fig. 7.

Fig. 9 is similar to Fig. 2 but shows a modification in which normaldriving of the cam is derived from the intermittent sewing machine feedexcept during the 180 degree non-sewing reversal of thework.

Fig. 10 is an end elevational view of the embodiment of Fig. 9.

A sewing machine 10 is mounted on a table 11 which has been modified byincluding a special cut-out section 12 forming a work support. Thesewing machine 10 is driven by an electric power transmitter 13controlled 2. by solenoids Sol. 1 and S01. 2. This solenoid-controlledtransmitter is described at some length in US. application Serial No.536,414, filed September 26, 1955, to which reference may be had for amore complete understand= ing of the operation of this device.

Secured beneath the table and. extending in spaced par= allel relationto the top work support 12 is a horizontal shelf 14 for slidablysupporting an annular cam 15 as will be explained. An electric cam-drivemotor 16 located beneath the cam-supporting shelf 14 drives a verticalshaft 17 through a speed reducer 18 and bevel gears 19. The shaftextends upward through the shelf and terminates in a toothed drive wheelor pinion 20 which engages the outer toothed periphery of the cam 15.The vertical shaft 17, it will be noted, is so located relatively to thesewing machine that the needle 21 is in line vertically with the contactline between the drive wheel and the cam periphery. In this manner itwill be seen from what follows that any turning of the work in order tofollow the predetermined contour path will always be substantially aboutthe needle axis. The cam 15 is continuous and annular, and has anoutline shape the same as the contour path of the seam to be made aswill be seen best in Fig. 3. Spaced idler rollers 2222 bear on the innerperiphery of the annular cam 15 and they are positioned relatively tothe drive wheel 20 to keep the tangent to the periphery of the cam atthe drive wheel in the direction of normal feed of the sewing machine 10as the cam 15 slides over the surface of the support 14 and is driven bythe drive wheel 20.

Reference to the details of Figs. 4 and 5 shows how pressure is appliedto the cam 15 to keep it in proper driving contact with the drive wheel20. The rollers 22-22 are spaced equally on opposite sides of acenterline XX which passes through the axis of the drive wheel 20 and isat right angles to the normal direction of sewing machine feed. Pivotpins 23-23 for the rollers 22-22 are secured to a T-block 24 which has astern portion 25 arranged to slide within ways to confine its motionalong the centerline. The ways comprise side members 26-26 and a topmember 27 secured to a horizontal platform 28 which also forms a supportfor the bearings 2929 in which the drive-wheel shaft 17 is journaled. Acompression spring 30 seated within a central recess 31 in the stemportion 25 reacts against a closure member 32 to urge the T-block 24 tothe right as shown, and with it, the rollers 22-22 urge the annular cam15 into driving contact with the drive wheel 20 as shown. A pull rod 33which passes axially through the center of the spring 30 and is threadedinto the T-block 24 is employed to pull the rollers 22-22 out ofengagement with the cam 15 so that it may be manually postioned ifnecessary. This arrangement provides an equal application of pressure onthe cam 15 at two points symmetrically spaced with relation to the drivewheel 20 and in a direction at right angles to the normal direction ofsewing machine feed, with the result that the cam tontour is urged intoa tangent position relatively to the normal line of feed.

As seen best in Figs. 1 and 2 a work-holder comprising two superposedhinged templates 34 and 35 is carried by a vertical post 36 whichextends downward through the aperture 37 of the cut-out section 12 andis adjustably secured in a socket member 38 fixed to a cross-bar 39which in turn is secured to the cam 1 5. The superposed templates 34 and35 have a peripheral shape conforming to and in register with the outerperiphery of the cam 15 but are somewhat smaller to allow the work blank40 to protrude at the edges to be engaged by the needle 21 of the sewingmachine 10. I

it -will be seen from the abovethat the feeding of the cam 15 by thedrive wheel 20 and the angular guiding 3 thereof by the rollers 22-22imparts to the work holder 34, 35 and the work 40 held therein a feedingand a turning action which closely simulates hand guiding action andresults in automatic movement of the material past the needle always inthe direction of the normal feed of the sewing machine as indicated bythe arrow R of Fig. 1 and Fig. 3.

Referring to the diagram of Fig. 6 and to Fig. 2, there will now bedescribed an electric control system for establishing an automatic cycleof operations for the contour sewing machine of this invention. In Fig.6 a polyphase line L supplies power for the cam drive motor 16 and themotor of the transmitter 13 while a transformer Tr furnishes power tothe control bus, a, b. With the work blank 40 clamped in the work holder34, 35 positioned as shown in Fig. 1, the operator pushes the motorstart button located at a push-button station 41. This energizes amagnetic starter M-2 to start the motor of the electric powertransmitter 13 in the customary manner. Once started, this motorcontinues to run as long as operations continue.

To initiate the sewing cycle, the operator pushes the cycle start buttonlocated at push-button station 42 to energize relay CRS which is lockedin through the nor mally-closed contacts of relays CR2 and CRR. Openingof normally-closed contacts of CRS deenergizes solenoid Sol. 2 torelease the transmitter brake and closure of normally-open contacts ofCRS energizes solenoid Sol. 1 to engage the transmitter clutch thusstarting the sewing machine. Relay CR1 is energized and is locked inthrough normally-closed contacts of a timer T-1. The timer T-l is alsoenergized, as is the magnetic starter M1 which thus starts and runs thecam drive motor 16 to feed the work 40 to the stitchinginstrumentalities of the sewing machine 10 in a predetermined path setby the peripheral shape of the annular cam 15. Some of the successivepositions of the cam 15 during this feeding of the work are seen in thedotted line views A, B, C and D of Fig. 3.

At the end of the time for which the timer T-l is set, at which time thework holder has reached approximately the position indicated in thedotted lines in Fig. 1, closure of normally-open contacts of timer T-lenergizes relay CR2 through normally-closed contacts of relay CRR.Opening of normally-closed contacts of timer T-1 deenergizes relay CR1and restores timer T-l to starting condition. Closure of normally-pencontacts of CR2 energizes relay CR3 through normally-closed contacts oftimer T-2. Opening of normally-closed contacts of CR2 deenergizes relayCRS, releases the clutch solenoid Sol. 1 and energizes the brakesolenoid Sol. 2 to stop the sewing machine. The magnetic starter M-1 isalso deenergized to stop the cam drive motor.

Closure of normally-open contacts of CR2 also energizes the timer T-2which starts timing to provide a delay to enable the operator to cut thethread before tfurther feeding of the material 40 by the cam drive motor16.

At the end of the period for which the timer T-2 is set, closure ofnormally-open contacts of T-Z energizes relay CR4 and timer T-3. Openingof normally-closed contacts of T-2 deenergizes CR3, and timer T-2 isrestored to starting condition. Closure of normally-open contacts of CR4energizes starter M-1 and the cam drive motor 16 starts and runs drivingthe work holder 34, 35 to its starting position, which period is timedout by the timer T3. Successive positions assumed by the cam 15 duringthis feeding period are indicated by the dot-dash line views E, F and Aof Fig. 3. At the end of the period for which T-3 is set, normallyclosedcontacts of T-3 open and deenergize relay CR4 to reset timer T-3.Opening of normally-open contacts of CR4 deenergizes the starter M-1 andstops the cam drive motor 16. This completes the normal cycle ofoperations of the contour machine. The operator opens the hinged workholder 34, 35, takes out the finished work piece 40, inserts a new blankand closes the holder in readiness for starting the next cycle.

With the selector switch at station 42 set to hand position relay CRH isenergized. Closure of normallyopen contacts of CRH permits starting ofthe sewing machine by pushing the machine start button but prevents allother automatic operations because normallyclosed contacts of CRH opento prevent operation of timer T-l, relay CR1 and starter M-1.

Normally-open contacts of CRH close to permit energizing starter M-1 byholding down the index start button at station 42 for manual control ofthe cam drive motor 16.

An emergency stop button is provided at station 42 and operates asfollows: closure of emergency stop button energizes relay CRR whosenormally-closed contacts open to deenergize relay CRS which releaseclutch solenoid Sol. 1 and energizes brake solenoid Sol. 2 to apply thebrake and stop the sewing machine 10. Opening of normally-open contactsof CRS deenergizes magnetic starter M-1 and stops the cam drive motor 16unless the cycle is on T3, in which case it will be stopped soon anyhow.Opening of normally-closed contacts of CRR deenergizes relay CR1, resetstimer T1, and deenergizes relay CR2. Opening of normally-open contactsof CR2 deenergizes relay CR3 and stops timer T-2.

A modified mechanism for driving the annular cam 15 is shown in Figs. 7and 8. In this case the rollers 41-41 are spaced equally on each side ofa center-line Y-Y which passes through the axis of the drive wheel 42and is at right angles to the normal direction of sewing machine feed.However, the rollers 41-41 are each mounted on separate slides 43-43which confine their movement to an individual linear back-and-forthmotion parallel to the center-line Y-Y. The slides 43-43 are confined tomove within a block 44 fixed to a base-plate 45 which serves as asupport for a bearing member 46 in which is journaled the shaft 47 forthe drive-wheel 42. Link elements 48-48 connect the slides with a commonfloating link 49 to the center of which is pivotally secured one end ofa lever 50 pivoted at 51 and having a handle 52 at the opposite end.Springs 53-53 secured at one end to pivot pins 54-54 are each adjustablyanchored at their other end in blocks 55-55 secured to the base-plate 45and provide individually adjustable bias for the rollers 41-41 to urgethem against the cam 15 and thus to maintain the cam 15 and drive wheel42 in proper driving contact. By manipulation of the handle 52 therollers 41-41 may be retracted and the cam drive disengaged. By means ofthis construction there is individual springing for each roller with adifierential lift action which enables the rollers to follow the camcontour easier and to maintain better control of the cam position inaccordance with the desired result of simulating precision hand guidingaction over stitching paths of compound curvature.

In the foregoing embodiments the work is fed past the needle at aconstant rate by a motor-driven cam and this is the preferred form. Itmay, however, be desirable at times to employ an intermittent feed forthe work, synchronized with the needle reciprocations, and amodification to accomplish this is illustrated in Figs. 9 and 10. Inthis case an eccentric cam 56 mounted on the armshaft 57 of the sewingmachine 10 engages the fork 58 of a pivoted lever 59 and imparts arising and falling movement to a link 60 connecting lever 59 and theouter element 61 of a conventional one-way clutch 62. This imparts anintermittent, one-way rotary movement to the shaft 63 and through gears64 and 65 to the shaft 17 and the cam driving wheel or pinion 20.

The cam-drive motor 16 is connected through the speed reducer 18,one-way clutch 66, and gears 67 and 65 to drive the shaft 17 and thewheel 20 only in the same direction as when driven by the shaft 63. Thecam-drive motor in this embodiment is needed only during the 180 degreereversal of the work to starting position during which the sewingmachine is inoperative and corresponds to the period represented by thedot-dash line views E, F and A of Fig. 3.

Since the cam-drive motor is always started by energizing the magneticstarter M-l, for the embodiment of Figs. 9 and 10 it is necessary tomodify the diagram of Fig. 6 merely by removing the normally-opencontacts of relay CR and the normally-closed contacts of relay CRH inseries with the starter M-l. These contacts are indicated specificallyat c and d in Fig. 6. This change makes the automatic control of thestarter M-l responsive only to the relay CR4 which is energized by thetimer T-2.

It will be apparent from the above that amost important structuralfeature of this invention is the position of the drive wheel 20 directlybelow the needle 21 combined with the presser action of the idlerrollers 22-22 to insure that the line of stitches is always in thedirection of the normal sewing machine feed at the needle regardless ofthe changing curvature of the contour path being followed.

Having thus set forth the nature of the invention, what I claim hereinis:

1. A machine for sewing automatically around a predetermined contour,comprising a sewing machine having a work-supporting surface and avertically reciprocatory needle, an apertured stationary shelf mountedto form a horizontal extension of the work-supporting surface, a secondstationary shelf mounted parallel to and below said first shelf, anannular cam shaped to conform in plan to the predetermined contour to bestitched and supported freely on said second shelf, a pinion projectingupwards through the second shelf and positioned directly below thesewing machine needle in driving contact with one periphery of theannular cam, two spaced idler wheels mounted on a plate spring-biasedtoward the pinion and bearing on the opposite periphery of the annularcam to maintain driving contact with the pinion, a workholding frameslidingly supported on said first shelf and secured to the annular camby an element which extends vertically through the aperture in the firstshelf, and means for driving said pinion to move the cam and frame sothat work held in said frame is moved under the reciprocatory needle toform stitches therein in a path con forming to the predeterminedcontour.

2. A machine for sewing automatically around a predetermined contour ofcompound curvature, comprising a sewing machine having a verticallyreciprocatory needle, an apertured stationary supporting plate mountedadjacent the needle to form a work support, a second stationarysupporting plate mounted parallel to and below said first plate, anannular cam shaped to conform in plan to the predetermined contour to bestitched and supported to be slidable freely on the second plate, apinion, projecting upwards through the second plate and positioneddirectly beneath the sewing machine needle, in driving con tact with oneperiphery of the annular cam, two spaced idler wheels mounted onyielding carriers and bearing on the opposite periphery of the annularcam to maintain proper driving contact with the pinion, a work-holderfreely supported to slide on said first plate and operatively connectedto the annular cam by a motion-transmitting link which extendsvertically through the aperture in the first plate, and means fordriving said pinion to move the cam and the work-holder so that workheldtherein is moved under the reciprocatory needle to form stitches inthe work in a path conforming to the predetermined contour.

References Cited in the file of this patent UNITED STATES PATENTS688,961 McDonald Dec. 17, 1901 2,142,476 McDonald Jan. 3, 1939 2,542,126Everett et a1 Feb. 20, 1951 2,702,016 Reece Feb. 15, 1955 2,722,903Larkin Nov. 8, 1955

